Operating out of a converted barn in rural goodland, Ind., Butler Tool and Design answered growing competition for tool and die work by performing direct manufacturing: building or "printing" parts layer-by-layer directly from 3D CAD models.
To this end, the shop purchased a sinterstation Pro230 SLS laser-sintering system from 3D Systems in Rock Hill, S.C.
Fast-forward in time, and the formerly small shop now includes an entire division called AdvaTech Manufacturing specifically to build parts with the new method.
"Direct manufacturing using the sinterstation requires no highcost molds or tooling, letting us provide affordable, low-quantity production," says owner James Butler. "For example, consider a job we recently completed, a 4 X 4 X 2.375-in. plastic injection-molded part. Tooling a mold for the part would have cost between $5,000 and $15,000, with a minimum per-piece cost between $167 and $500 for the thirty-part run. This doesn't even account for material and labor costs. The Sinterstation let us produce the parts for only $2,100, or $70 each. And part development took only two days from design to completion. In contrast, tooling the mold would have taken 4 to 16 weeks. And once the mold was produced, changes in part design would become more costly and time consuming."
Butler says direct manufacturing frees engineers from compromising on factors such as mold draft angles and machining access. Traditional manufacturing methods often force a part's entire geometry to change so molding or machining is feasible.
"We now design for function, not manufacturability," says Butler. "Better yet, new materials let us make parts even stronger than those injection-molded from plastics. For example, DuraForm EX from the sinterstation developer has an ultimate tensile strength of 48 MPa, higher than that of ABs and common polypropylene plastics, and a 47% elongation at break."